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View Full Version : Renewing the velvet "bearings" in early Ross sleeve and barrel lenses



Steven Tribe
13-Jun-2012, 09:41
I have only a few of these and discovered first to-day that there are two velvet seals set into the edges of the sleeve to reduce clearance and provide a non abrasive movement. These are present in serial numbers 11445, 16819 and 17142 and probably for a wider range of serial numbers.

There is only occasionally any reason to remove the sleeve - in fact it can be quite a problem with tangential drives as the brass screws have very short threads cut the barrel.
The basic colour of the velvet is (at least, now anyway) black. The lens I took apart had lost both the velvet seals and there was plenty of verdigris in the turned depression which needed to be cleaned out.
I have bad experiences with modern types of velvet material as the threads tend to come loose when cut to size. I found a reel of ribbon which behaves much more politely when cut.
Before and after photographs below.
Purple was the only reasonable colour available!

BrianShaw
13-Jun-2012, 12:22
You always seem to have interesting challenges... and interesting solutions to share!

Purple looks good to me!

Steven Tribe
13-Jun-2012, 14:47
Did any other maker use this system? While it may seem like a good idea, quite a lot of metal is removed from the thin edge by the Waterhouse cut-out in the brass turning operation. I have had to solder a repair on one of mine at this exact place.
I don't have later Ross types with sleeves so I don't know when/if they abandoned the system?

Jason Greenberg Motamedi
13-Jun-2012, 15:39
I have replaced the seals in a few 1850s or 1860s Harrison and HBH lenses which used velvet. Like yourself I ended up using velvet ribbon, although the quality of the ribbon--at least that which I could find locally--was not very high. I seem to recall replacing the seal on an 1860s Dallmeyer also.

TheDeardorffGuy
13-Jun-2012, 16:10
Deardorffs have velvets on the front also. To avoid the unraveling of the threads you can spray the back side with fray check. Get it at a fabric store. I restored a L.F. Deardorff Portrait lens that had the thinest velvet I ever saw. I thought it was worn out. I replaced it with modern type and the lens barrel would not fit. A real simple fix. Tape the velvet to a flat surface. On either side lay some Evergreen styrene (from a hobby shop) of the correct thickness and go over it with an electric razor. Not a floating 3 head type. It works great.

Steven Tribe
14-Jun-2012, 02:04
Good advice!

This system must be quite common - removing the sleeve just hasn't been necessary for me until now.
A recently acquired large Darlot/Jamin was also missing the both seals. This is a more substantial sleeve than the Ross and the velvet seal continues across the Waterhouse cut out.

E. von Hoegh
14-Jun-2012, 11:59
Did any other maker use this system? While it may seem like a good idea, quite a lot of metal is removed from the thin edge by the Waterhouse cut-out in the brass turning operation. I have had to solder a repair on one of mine at this exact place.
I don't have later Ross types with sleeves so I don't know when/if they abandoned the system?

Most if not all makers of multi-draw spyglasses used it, it was used in some opera glasses as well.

I frigged around for hours, gluing the edges of cut velvet to redo a 4-draw S. Bardou spyglass; ribbon never occurred to me..... would have been a 100~ mile round trip to get some, anyway.

Steven Tribe
14-Jun-2012, 14:26
Ask your female contacts about velvet ribbon - they probably know how to order on the net! Whilst we are using our time here, they are looking at quite different sites! A google search with velvet ribbon 1/4" gives quite a few netshop sources. Prices are around 6usd for a lifetime's supply - many colours available including black. Ribbon velvet is much thinner than meter material = more suitable!

Beg to differ about felt/velvet bearings. I have taken apart about 10 spyglasses from the UK and Germany (1780 - 1850) and not one of them had anything except the internal split "sprung" brass short brass tube to take up the "wobble". The presence of velvet may be a sign of "unauthorised" - but probably practical - repair.

Steven Tribe
22-Feb-2013, 11:46
Just done a new velvet bearing.
This is a small CdV/1/4 plate Perken,Son & Rayment Petzval.
This one had just a single seal cut out (nearest the flange) and it looks like the maker never bothered to install the velvet!
A sign that the lens was made by someone else for sale by Perken?

goamules
27-Feb-2013, 07:39
I have an early Voigtlander that appears to have dark green velvet for the seal/bearing. I bet they all used something to avoid scratching the brass.